Methods for production of a plasma display panel

ABSTRACT

Disclosed is a method for producing a patterned calcined inorganic film such as an electroconducting or insulating (non-conductive) film, particularly a plasma display panel, embracing a calcining step. To produce a patterned calcined inorganic film without inducing warpage, shrinkage of line width, or breakage of patterned lines, a patterned film formed on a substrate with a composition containing a heat decomposable binder and particles of an inorganic material is covered, prior to the calcining step, with a coating film of a heat decomposable resin composition capable of hardening or drying at a temperature lower than the temperature at which the heat decomposable binder is thermally decomposed and further capable of being burned off below the highest temperature of the calcining profile and thereafter the calcining step is performed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to methods for the production of a patternedcalcined inorganic film and a plasma display panel. More particularly,this invention relates to a technique for calcining a patterned filmwithout inducing warpage, shrinkage of line width, etc. in the formationof a circuit on a ceramic substrate, the manufacture of a photoelectrictube, the manufacture of an electroconductive film or an insulating filmon the front substrate or the back substrate of a plasma display panel,and the formation of a fluorescent film.

2. Description of the Prior Art

In recent years, the demand for conductor circuit patterns of increaseddensity and heightened fineness has been escalating in the field ofcircuit substrates, displays, and the like. As a result, thedesirability of developing a patterning technique which is capable offorming highly fine patterns with high reliability has been findingrecognition.

When a patterned calcined inorganic film is produced by using acomposition containing a heat decomposable binder and particles of aninorganic material, forming on a substrate a patterned film of thecomposition by the printing technique or photolithographic technique,and calcining this film thereby burning off the heat decomposablebinder, there arises a peculiar problem which is attendant on theoperation of calcination. Now, this problem will be explained below withreference to a plasma display panel (hereinafter abbreviated as "PDP"),for example.

The PDP is a planar display for exhibiting pictures and pieces ofinformation by utilizing the light emitted by plasma discharge. It isclassified under the DC type and the AC type according to the structureof panel and the mode of driving. The principle of color display by thePDP consists in generating plasma discharge in cells (discharge spaces)between two opposed electrodes severally formed on a front glasssubstrate and a back glass substrate separated by intervening ribs(barriers), and exciting the phosphor formed on the inner surface of theback glass substrate with the ultraviolet light generated by thedischarge of such a gas as He or Xe sealed in the cells thereby inducinggeneration of visible lights of three primary colors. The cells in theDC type PDP are divided by the component ribs of a lattice, whereasthose in the AC type PDP are divided by the ribs which are parallellyarranged on the face of the substrate. In either case, the cells aredivided by ribs.

FIG. 1 illustrates a typical construction of the planar discharge typePDP using a three-electrode structure for full color display. On thelower face of a front glass substrate 1, many pairs of displayelectrodes 2a, 2b each comprising a transparent electrode 3a or 3bintended for discharge and a bus electrode 4a or 4b intended forlowering the line resistance of the transparent electrode are formed. Onthe display electrodes 2a, 2b, a transparent dielectric layer 5 (lowmelting glass) for accumulating electric charge is formed by printingand calcination. A protective layer (MgO) 6 is formed thereon by vacuumdeposition. The protective layer 6 assumes the role of protecting thedisplay electrodes and maintaining the state of discharge.

On a back glass substrate 7, ribs (barriers) 8 shaped like stripes andadapted to partition discharge spaces and address electrodes (dataelectrodes) 9 severally disposed in the discharge spaces are formed withprescribed pitches. On the inner faces of discharge spaces, fluorescentfilms of the three colors, i.e. red (10a), blue (10b), and green (10c),are laid out regularly. In the full color display, the fluorescent filmsof the three primary colors of red, blue, and green mentioned abovejointly form one picture element.

The PDP described above is called a "planar discharge system" because anAC pulse voltage is applied between the pair of display electrodes 2a,2b to induce discharge between the electrodes on one and the samesubstrate. It has a construction such that the ultraviolet lightgenerated by discharge excites the fluorescent films 10a, 10b, and 10cof the back substrate 7 and the visible light consequently generated isseen through the transparent electrodes 3a, 3b of the front substrate 1(reflection type).

The formation of the bus electrodes 4a, 4b mentioned above has beenheretofore attained by a process which comprises forming three Cr/Cu/Crlayers by vacuum deposition or sputtering on the transparent electrodeand then patterning the layers by the photolithographic technique. Sincethis process suffers copiousness of component steps and high cost ofproduction, in recent years, a process which comprises screen printing aconductive paste such as of silver and then calcining the layer of thepaste or, for the purpose of imparting to a pattern a line width of notmore than 150 μm, a process which comprises applying a photosensitiveconductive paste to the transparent electrode, exposing the layer of thepaste to light through a pattern mask, developing the exposed layer, andsubsequently calcining the developed layer has come to take the place ofthe former process.

The calcining step, however, has encountered the problem of exposing thebus electrodes 4a, 4b to warpage, as shown in FIG. 2, to shrinkage ofline width, and to accidental breakage. Not only when the breakage ofelectrode lines occurs but also when the shrinkage of line width occurs,the problem arises that the PDP ceases to operate normally because thebus electrodes are no longer capable of accomplishing the primary objectthereof to lower the line resistance of the transparent electrodes 3a,3b. When the bus electrodes 4a, 4b develops warpage, the problem ensuesthat the bus electrodes become liable to cause a short circuit becausethe dielectric layer on the warped parts of the bus electrodes suffers adecrease in thickness.

The problem of entailing the warpage, shrinkage of line width, andbreakage of electrode lines subsequent to the calcination mentionedabove occurs not only in the bus electrodes 4a, 4b but also in theaddress electrodes 9.

The address electrodes 9 are manufactured by forming a patterned layerof an electroconductive paste containing an electroconductive power ofAg, Au, Pd, Ni, Cu, Al, Pt, or the like on the back glass substrate 7and calcining the layer at a temperature in the approximate range of500° to 600° C. For the formation of the pattern of theelectroconductive paste, the printing method, the lift-off method (themethod which comprises laminating a photosensitive dry film onto asubstrate throughout the whole surface thereof, patterning the film onthe substrate, filling up grooves opened in the film with anelectroconductive paste, drying and hardening the paste, then removingthe dry film, and calcining the hardened paste; otherwise called "dryfilm filling method"), and the method of patterning a photosensitiveelectroconductive paste by photolithography (the method which comprisesapplying a photosensitive electroconductive paste to a substrate, dryingthe applied layer of the paste, exposing the dry layer to light througha pattern mask, developing the exposed areas, and calcining thedeveloped layer) are adopted. The address electrodes likewise suffer theproblem of encountering such difficulties as warpage, shrinkage of linewidth and breakage of electrode lines during the course of calcinationand preventing the PDP from normally operating.

The problems to be encountered in the manufacture of a conductor patternas described above are not limited to the PDP. They also occur invarious other operations such as, for example, forming a circuit byforming a patterned circuit of an electrodoncuctive paste orphotosensitive conductive paste on a ceramic substrate and calcining thepatterned circuit and forming a conductor pattern through a calciningstep as in the manufacture of a photoelectric tube.

They occur not only in the formation of a conductor pattern but also inthe formation of a nonconductor (insulator) pattern. In the PDPmentioned above, for example, the formation of ribs (barriers) iseffected by the printing method which comprises performing the work ofprinting and drying a glass paste by screen printing on a glasssubstrate up to eight-ten-odds repetitions till the superposed layers ina prescribed pattern amount to a prescribed thickness (about 100-150 μm)and then calcining the superposed layers of glass paste; thesandblasting method which comprises applying glass paste to a glasssubstrate throughout the entire surface till a prescribed thickness,scraping out grooves in the layer of glass paste to a prescribed patternby blowing blast powder thereto through a pattern mask formed byphotolithography and vested with an ability to resist blasting, and thencalcining the patterned layer; and the lift-off method (dry film fillingmethod) which comprises laminating a photosensitive dry film of aprescribed thickness onto a glass substrate, forming grooves in the filmby photolithography in the prescribed shape of ribs, applying glasspaste so as to fill up the grooves, drying and hardening the glasspaste, removing the photosensitive dry film from the substrate, andcalcining the glass paste.

The ribs formed on the PDP back substrate are intended to confine theluminous discharge within a fixed area so as to preclude false dischargeor cross talk between adjacent discharge cells and ensure ideal display.They are endowed with the function of retaining uniform discharge spacesowing to their own height, width, and pattern gap and enhancing themechanical strength of the whole panel. In order for the PDP to acquirehigh luminance, it is necessary that the discharge gas spaces be as wideas permissible and the ribs be as thin as possible. Specifically, it isnecessary to form ribs which have a large aspect ratio (ratio of heightto width), a narrow width, a great height, and fully sufficientstrength.

When the warpage or the shrinkage of line width occurs during the courseof calcining ribs mentioned above, the ribs acquire only disfiguredskirts and inaccurate heights and the display cells suffer their shapeto be heavily affected by blurred borders of the ribs and the paneleventually obtained displays pictures of inferior quality.

When the warpage or the shrinkage occurs in the formation of afluorescent film, it possibly cause a crack or peeling of the film andimpairs the quality of display and degrades the yield.

SUMMARY OF THE INVENTION

In view of such problems as mentioned above, a primary object of thepresent invention is to provide, for the calcining process involved inthe manufacture of a patterned electroconductive or insulating(nonconductive) film, a method which is capable of producing a patternedcalcined inorganic film without inducing warpage, shrinkage of linewidth or brekage of patterned lines.

A further object of the present invention is to provide a method for theproduction of a PDP, which method is capable of producing a highly fineelectroconductive film of bus electrodes or address electrodes,insulating film of ribs or fluorescent film with high accuracy withoutinflicting warpage, shrinkage of line width or cracks.

To accomplish the objects mentioned above, the first aspect of thepresent invention provides a method for the production of a patternedcalcined inorganic film by performing a calcining operation on apatterned film of a composition containing a heat decomposable binderand particles of an inorganic material formed on a substrate,characterized by the fact that prior to the calcining step mentionedabove, the film mentioned above is covered with a coating film of a heatdecomposable resin composition capable of hardening or drying at atemperature lower than the temperature at which the heat decomposablebinder is thermally decomposed and further capable of being burned of fat a temperature not more than the highest temperature of the calciningprofile (temperature control profile of the calcining step) andthereafter the calcining step mentioned above is performed.

The second aspect of the present invention provides a method for theproduction of the PDP by the use of the calcining technique describedabove.

In the first mode of embodiment of the method for the production of thePDP including the steps of patterning a film of a composition containinga heat decomposable binder and particles of an inorganic material formedon a substrate and calcining the film thereby burning off the heatdecomposable binder and consequently forming on the substrate apatterned electroconducting or insulating film made of the inorganicmaterial, the method is characterized by the fact that prior to thecalcining step mentioned above, the film mentioned above is covered witha coating film of a heat decomposable resin composition capable ofhardening or drying at a temperature lower than the temperature at whichthe heat decomposable binder is thermally decomposed and further capableof being burned off at a temperature not more than the highesttemperature of the calcining profile and thereafter the calcining stepmentioned above is performed.

In the second mode of embodiment of the method for the production of thePDP including a film-forming step of forming on a substrate a coatingfilm of a pasty composition containing a heat decomposable binder andparticles of an inorganic material and possessing an ability to renderitself, on exposure to light, insoluble in a developing solution, anexposing step of selectively exposing the film to light therebyphotocuring the exposed portion of the film, a developing step ofremoving the unexposed portion of the film with a developing solution,and a calcining step of calcining the photocured film together with thesubstrate thereby burning off the heat decomposable binder in the filmand consequently forming on the substrate a patterned electroconductingor insulating film of the inorganic material, the method ischaracterized by the fact that prior to the calcining step mentionedabove, the photocured film is covered with a coating film of a liquidheat decomposable resin composition capable of hardening or drying at atemperature lower than the temperature at which the heat decomposablebinder is thermally decomposed and further capable of being burned offat a temperature not more than the highest temperature of the calciningprofile and thereafter the calcining step mentioned above is performed.

In the third mode of embodiment of the method for the production of thePDP including a film-forming step of forming on a substrate a coatingfilm of a pasty composition containing a heat decomposable binder andparticles of an inorganic material and possessing an ability to renderitself, on drying or hardening, susceptible of an abrading work withblast powder (abrasive), a resist-forming step of laminating ablast-resistant photosensitive dry film on the coating film, selectivelyexposing the photosensitive dry film to light, and then developing thedry film thereby forming a blast-resistant film possessing a prescribedmasking pattern, a blasting step of blowing blast powder to the filmsthereby cutting the portion of the coating film exposed through theblast-resistant film to give a patterned film, a peeling step ofremoving the bast-resistant film with a remover or peeling liquid, and acalcining step of calcining the blast-worked patterned film togetherwith the substrate thereby burning off the heat decomposable binder inthe patterned film and consequently forming on the substrate a patternedelectroconducting or insulating film of the inorganic material, themethod is characterized by the fact that prior to the calcining stepmentioned above, the patterned film mentioned above is covered with acoating film of a liquid heat decomposable resin composition capable ofhardening or drying at a temperature lower than the temperature at whichthe heat decomposable binder is thermally decomposed and further capableof being burned off at a temperature not more than the highesttemperature of the calcining profile and thereafter the calcining stepmentioned above is performed.

In the fourth mode of embodiment of the method for the production of thePDP including a filling step of applying a pasty composition containinga heat decomposable binder and particles of an inorganic material in aprescribed thickness to a dry film having grooves on a substrate so asto fill up the grooves and drying and hardening the composition, apolishing step of polishing the film of the hardened composition tillthe dry film appears to the surface, a peeling step of immersing the dryfilm and the substrate in a remover to swell and peel off the dry filmthereby leaving a patterned film of the hardened composition, and acalcining step of calcining the patterned film of the hardenedcomposition together with the substrate thereby burning off the heatdecomposable binder in the hardened composition and consequently formingon the substrate a patterned electroconducting or insulating film of theinorganic material, the method is characterized by the fact that priorto the calcining step mentioned above, the patterned film of thehardened composition is covered with a coating film of a liquid heatdecomposable resin composition capable of hardening or drying at atemperature lower than the temperature at which the heat decomposablebinder is thermally decomposed and further capable of being burned offat a temperature not more than the highest temperature of the calciningprofile and thereafter the calcining step mentioned above is performed.

In the fifth mode of embodiment of the method for the production of thePDP including a printing step of forming on a substrate by the screenprinting technique a film of a prescribed pattern of a pasty compositioncontaining a heat decomposable binder and particles of an inorganicmaterial and possessing an ability to render itself, on drying orhardening, capable of retaining the shape thereof and a calcining stepof calcining the film together with the substrate thereby burning offthe heat decomposable binder in the film and forming on the substrate apatterned electroconducting or insulating film of the inorganicmaterial, the method is characterized by the fact that prior to thecalcining step mentioned above, the film of the prescribed pattern iscovered with a coating film of a liquid heat decomposable resincomposition capable of hardening or drying at a temperature lower thanthe temperature at which the heat decomposable binder is thermallydecomposed and further capable of being burned off at a temperature notmore than the highest temperature of the calcining profile andthereafter the calcining step mentioned above is performed.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features, and advantages of the invention will becomeapparent from the following description taken together with thedrawings, in which:

FIG. 1 is a fragmentary exploded perspective view of the AC type PDP ofthe planar discharge system;

FIG. 2 is a fragmentary sectional side view schematically illustratingthe bus electrodes of the front substrate of the PDP in a warped state;

FIGS. 3A through 3E are fragmentary sectional side views for anexplanation of process flow illustrating one embodiment of the method ofthe present invention;

FIGS. 4A through 4G are fragmentary sectional side views for anexplanation of process flow illustrating another embodiment of themethod of the present invention;

FIGS. 5A through 5G are fragmentary sectional side views for anexplanation of process flow illustrating yet another embodiment of themethod of the present invention; and

FIGS. 6A through 6C are graphs showing profiles of the surface of a filmmanufactured in Example 4 as produced by a surface roughness meter atvarious stages of the manufacture.

DETAILED DESCRIPTION OF THE INVENTION

The present inventors have made a diligent study concerning suchphenomena as warpage, shrinkage of line width, and breakage of patternedlines which occur in the process of producing a patterned calcinedinorganic film by performing a calcining operation on a patterned filmformed on a substrate with a composition containing a heat decomposablebinder and particles of an inorganic material. They have consequentlyfound that these phenomena occur at the stage of removing the binder byheating the film and not at the stage of calcination. To be specific,the temperature control profile of the calcining step generally consistsof two stages, i.e. the stage of heating the film to a high temperaturelower than about 500° C. and retaining it at the temperature therebyremoving (burning off) the binder from the film and the calcining stageof further heating the film to a temperature not lower than about 500°C. and retaining the film at that temperature. The phenomena mentionedabove occur at the stage of removing the binder from the film. It issuspected, therefore, that at the stage of removing the binder from thefilm, the binder component in the composition is not burned offuniformly throughout the entire web of the film but is burned outpreferentially in the surface part of the film and, consequently, thefilm begins to shrink from the surface part inward and this shrinkage isfollowed by the warping or the shrinkage of line width. Particularlywhere the patterning operation performed on the film embraces the stepof exposure to light and the step of development, the phenomenamentioned above are liable to occur when the development produces anundercut.

The present inventors, after continuing a diligent study in search of amethod capable of preventing the aforementioned phenomena, havediscovered that a finely patterned calcined inorganic film can be formedwithout inducing warpage, shrinkage of line width, or breakage ofpatterned lines by a method which comprises covering the patterned filmmentioned above with a coating film of a heat decomposable resincomposition capable of hardening or drying at a temperature lower thanthe temperature at which the heat decomposable binder mentioned above isthermally decomposed and further capable of being burned off at atemperature not more than the highest temperature of the calciningprofile prior to the calcining step mentioned above and thereafterperforming the calcining step mentioned above. A coating of the heatdecomposable resin composition applied to the patterned film may bedried, thermally cured or photocured prior to the calcining step,depending on the composition used.

This operation may be explained as follows. By having the patterned filmcoated with a coating film of the heat decomposable resin compositionmentioned above prior to the step of calcination, the resin component inthe coating film and the binder component in the patterned film areuniformly burned out at the stage of removing the binder. Further, bythe coating film, the patterned film is retained fast on the surface ofthe substrate and prevented from inducing warpage or shrinkage. Sincethe patterned film is subjected in this state to the removal of thebinder and the calcination, the heat decomposable resin in the coatingfilm and the heat decomposable binder in the patterned film are burnedoff by thermal decomposition and the patterned calcined inorganic filmto be consequently produced is free from warpage, shrinkage, or breakageof patterned lines. It is also conceivable that the coating compositionintervenes between the patterned lines of the film and, by contactingthe end faces thereof and consequently exerting surface tension thereon,contributes to the prevention of the shrinkage.

It is evident from the explanation given above that the presentinvention can be applied to all the methods that are used for theformation of the patterned calcined inorganic film and does not need tobe limited to any specific technical field. The calcined inorganic filmmay be an electroconducting film or an insulating film, whichever suitsthe occasion. In the case of an electroconducting film such as for thebus electrodes or address electrodes of the PDP or the conductor circuitof the circuit board, for example, the electroconductive powder of Ag,Au, Pd, Ni, Cu, Al, or Pt and the low melting glass frit having amelting point befitting the calcination temperature are usable for theparticles of an inorganic material. In the case of the insulating filmsuch as the ribs in the PDP, the low melting glass frit and theinorganic pigment are usable for the particles. Besides, ceramics suchas alumina, silica, zircon, cordierite, and titanium dioxide may beused. The glass frit which is used favorably herein is a low-meltingglass having a softening point in the range of 300° to 600° C.,preferably containing lead oxide, bismuth oxide, or zinc oxide as a maincomponent and having an average particle diameter of not more than 10μm.

One preferable example of the PbO-based glass frit is an amorphous fritwhich is composed of (in percent by weight of oxide basis) 48-82% ofPbO, 0.5-22% of B₂ O₃, 3-32% of SiO₂, 0-12% of Al₂ O₃, 0-10% of BaO,0-15% of ZnO, 0-2.5% of TiO₂, and 0-25% of Bi₂ O₃ and has a softeningpoint in the range of 420-590° C.

One preferable example of the Bi₂ O₃ -based glass frit is an amorphousfrit which is composed of (in percent by weight of oxide basis) 35-88%of Bi₂ O₃, 5-30% of B₂ O₃, 0-20% of SiO₂, 0-5% of Al₂ O₃, 1-25% of BaO,and 1-20% of ZnO and has a softening point in the range of 420-590° C.

One preferable example of the ZnO-based glass frit is an amorphous fritwhich is composed of (in percent by weight of oxide basis) 25-60% ofZnO, 2-15% of K₂ O, 25-45% of B₂ O₃, 1-7% of SiO₂, 0-10% of Al₂ O₃,0-20% of BaO, and 0-10% of MgO and has a softening point in the range of420-590° C.

The various resins and organic compounds heretofore known to the art areusable for the heat decomposable binder. For the production of thephotosensitive paste, the photosensitive organic components(photosensitive prepolymers or photopolymerizable monomers or oligomers)and the photopolymerization initiators or sensitizers are usable.Further, such additives as pigments, dyes, silane coupling agents,leveling agents, and antiblocking agents may be properly incorporatedtherein, depending on the calcined film aimed at.

The paste to be used for the formation of the patterned film contains aheat decomposable binder and an inorganic material as essensialcomponents. It is used as diluted with a solvent so as to acquireviscosity fit for the intended use. The other components may be propertyincorporated in the paste to suit the calcined film aimed at. Thus,various species of paste known to the art to be usable for the formationof such calcined inorganic films as disclosed, for example, in publishedJapanese Patent Application, KOKAI (Early Publication) No. (hereinafterreferred to briefly as "JP-A-") 5-94,716, JP-A-5-67,405, JP-A-8-227,153,JP-A-9-142,878, JP-A-6-56,461, JP-A-8-55,575, JP-A-8-171,863, andJP-A-2-124,744 can be adopted. The teachings of the patentspecifications mentioned above are hereby incorporated by reference. Inthe formation of the bus electrodes of the PDP, the procedure whichcomprises applying by printing a patterned black layer of a silver pasteincorporating therein a black pigment for the purpose of impartingcontrast, drying the applied layer of the paste, then superposingthereon by printing a white layer of a silver paste for the purpose oflowering the resistance increased in consequence of the addition of thepigment, and subsequently performing the calcining step is popularlyadopted besides the procedure which comprises applying by printing onlyone patterned white layer of a conductor layer such as, for example, asilver paste. Of course, the present invention can be applied to thecalcination of such a superposed film as just mentioned.

Preferably, the heat decomposable resin composition for coating thepatterned film mentioned above is in a liquid state so as to adhere fastto the film throughout to the corner parts of the edges thereof. Thecoating film which is formed with this composition has only to becapable of hardening or drying at a temperature lower than thetemperature at which the heat decomposable binder succumbs to thermaldecomposition and further capable of being burned out by thermaldecomposition at a temperature not more than the highest temperature ofthe calcination profile, but does not need to be limited to any specifictype. For the purpose of retaining the sintered particles of aninorganic material in the patterned film fast to the surface of thesubstrate as long as possible and precluding the occurrence of warpageor shrinkage of line width during the course of calcination, the heatdecomposable resin in the coating film is required to possess a heatdecomposition temperature substantially equal to or slightly higher thanthe heat decomposition temperature of the heat decomposable bindermentioned above so that the thermal decomposition occurs substantiallyat the same time in the resin and the binder.

As the heat decomposable resin composition for use in the presentinvention, various kinds of resin composition such as drying resincompositions, thermosetting resin compositions, and photocurable resincompositions can be adopted. The term "drying resin composition" as usedherein means a resin composition which can form a film in consequence ofthe expulsion of the solvent by drying. The term "thermosetting resincomposition" means a composition which forms a resin film when it iscured by the intermolecular cross-linkage caused by the action of heator a catalyst. The term "photocurable resin composition" means acomposition which forms a resin film when it is cured by theintermolecular cross-linkage caused by the action of such an active rayas ultraviolet light, near infrared rays, infrared rays, or electronrays. A film-forming component (resin, oligomer, or compound) may besolved or dispersed, when necessary, in a solvent and adjusted to alevel of viscosity suitable for the method of application, and put touse. The use of the solvent may be omitted when the film-formingcomponent itself is a liquid. The term "heat decomposable resincomposition" as used in the present invention means a composition whichcan form a resin film when it is dried or hardened as mentioned above.The film-forming component itself does not need to be limited to a resinbut may be such a compound as, for example, a photopolymerizablemonomer.

Where the film-forming component is a resin, the resin may be at leastone member selected arbitrarily from among various resins includingacrylic polyols, polyvinyl alcohol, polyvinyl acetal, styrene-allylalcohol resin, phenolic resin, olefinic hydroxyl group-containingpolymers, cellulose derivatives such as methyl cellulose, ethylcellulose, and hydroxyethyl cellulose, ethylene-vinyl acetate copolymer,alkyd resin, alkyd phenol resin, butyral resin, epoxy resin, modifiedepoxy resin, acrylic resin, polyurethane resin, and polyester resins.Optionally, the resin can be used in combination with a curing catalystsuch as a peroxide or acid catalyst. The resin composition is allowed toincorporate therein, as occasion demands, various additives such asorganic pigments, plasticizers, antifoaming agents, leveling agents,antoiblocking agents, and silane coupling agents.

The film-forming component for the photocurable resin composition may beselected arbitrarily from among various known photosensitive resins(photosensitive prepolymers) such as the resins possessing suchethylenically unsaturated bonds as vinyl group, allyl group, acryloylgroup, and methacryloyl group and photosensitve groups such as propargylgroup, the acrylic copolymers possessing an ethylenically unsaturatedgroup, for example, in the side chain thereof, the unsaturatedcarboxylic acid-modified epoxy resin, and the resins formed by adding ananhydrous polybasic acid to the unsaturated carboxylic acid-modifiedepoxy resin. The compounds possessing at least one ethylenicallyunsaturated bond in the molecule thereof, namely the photopolymerizablemonomers or oligomers, are also usable. Such a photocurable film-formingcomponent is used in combination with a photopolymerization initiatorand/or a photopolymerization accelerator. The photopolymerizablemonomers among other components mentioned above are mostly in a liquidstate and enjoy the advantage of obviating the necessity for an organicsolvent.

Typical examples of the photopolymerizable monomers mentioned aboveinclude, but are not limited to: 2-hydroxyethyl acrylate,2-hydroxypropyl acrylate, N-vinylpyrrolidone, acryloyl morpholine,methoxytetraethylene glycol acrylate, methoxypolyethylene glycolacrylate, polyethylene glycol diacrylate, N,N-dimethyl acrylamide,N-methylol acrylamide, N,N-dimethylaminopropyl acrylamide,N,N-dimethylaminoethyl acrylate, N,N-dimethylaminopropyl acrylate,melamine acrylate, diethylene glycol diacrylate, triethylene glycoldiacrylate, propylene glycol diacrylate, dipropylene glycol diacrylate,tripropylene glycol diacrylate, polypropylene glycol diacrylate,phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, cyclohexyl acrylate,glycerin diglycidyl ether diacrylate, glycerin triglycidyl ethertriacrylate, isobornyl acrylate, cyclopentadiene mono- or di-acrylate;polyfunctional acrylates of polyhydric alcohols such as hexane diol,trimethylol propane, pentaerythritol, ditrimethylol propane,dipentaerythritol, and tris-hydroxyethyl isocyanurate and of ethyleneoxide or propylene oxide adducts thereof; methacrylates corresponding tothe acrylates enumerated above; and mono-, di-, tri-, and higherpolyesters of polybasic acids with hydroxyalkyl (meth)acrylates.

Examples of the photopolymerization initiators or sensitizers include,but are not limited to: acetophenones such as acetophenone,2,2-diethoxy-2-phenyl acetophenone, p-dimethylaminopropiophenone,dichloroacetophenone, trichloroacetophenone, p-tert-butyltrichloroacetophenone,2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, and2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one;benzophenones such as benzophenone, 2-chlorobenzophenone,p,p-dichlorobenzophenone, p,p-bis(dimethylamino)benzophenone,p,p-bis(diethylamino)benzophenone, and 4-benzoyl-4'-methyldiphenylsulfide; benzil; benzoin; benzoic ethers such as benzoin methyl ether,benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutylether; ketals such as benzyl dimethyl ketal; thioxanthones such asthioxanthone, 2-chlorothioxanthone, and 2,4-diethylthioxanthone;anthraquinones such as 2-ethylanthraquinone and2,3-diphenylanthraquinone; organic peroxides such as benzoyl peroxideand cumene peroxide; thiol compounds such as dimer of 2,4,5-triarylimidazole, riboflavin tetrabutylate, 2-mercaptobenzimidazole,2-mercaptobenzoxazole, and 2-mercaptobenzothiazole; organic halogencompounds such as 2,4,6-tris-S-triazine, 2,2,2-tribromoethanol, andtribromomethylphenyl sulfone; and 2,4,6-trimethylbenzoyl diphenylphosphine oxide. These compounds may be used either singly or in theform of a combination of two or more members. The amount of theaforementioned photopolymerization initiator to be incorporated in thecomposition suitably falls in the range of 0.1 to 30 parts by weight,based on 100 parts by weight of the aforementioned photosensitiveorganic component (photosensitive prepolymer or photopolymerizablemonomer).

The film-forming component mentioned above can be selected properly tosuit the heat decomposable binder in the patterned film to be used.Properly, it has a burning-off point in the approximate range of300-600° C., preferably 400-570° C., so as to be burned off by thermaldecomposition during the course of calcination substantiallysimultaneously with the heat decomposable binder in the film. The term"burning-off point" as used herein means the temperature which existswhen the per cent loss in weight of the organic component, excluding thesolvent, reaches 95% as determined in the air at the temperatureincreasing rate of 5° C./minute by the thermogravimetric analysis(TG/DTA). It is particularly favorable to use a film-forming componentwhich is identical with or analogous (in pyrolytic behavior or chemicalstructure) to the heat decomposable binder. For instance, thefilm-forming component may have a burning-off point substantially equalto that of the heat decomposable binder.

The heat decomposable resin composition of the present invention, forthe purpose of solving the film-forming component or adjusting theviscosity of the composition itself, allows the use therein of a varyingorganic solvent. As concrete examples of the organic solvent, ketonessuch as methylethyl ketone and cyclohexanone, aromatic hydrocarbons suchas toluene, xylene, and tetramethyl benzene, glycol ethers such asdiethylene glycol monoethyl ether and dipropylene glycol diethyl ether,esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate,and carbitol acetate, aliphatic hydrocarbons such as octane and decane,and petroleum solvents such as petroleum ether, petroleum naphtha, andsolvent naphtha may be cited. In terms of toxicity and coatingproperties, glycol ethers, esters, and petroleum solvents are usedparticularly favorably. For the purpose of avoiding abrupt vaporizationof solvent during the course of removal of binder, it is advantageous touse a high boiling solvent among other organic solvents enumeratedabove.

Now, the method of the present invention will be described below byreference to the accompanying drawings which depict various modes ofapplication of the method to the production of PDP.

FIGS. 3A through 3E represent the mode using a photosensitive paste forthe production of a calcined film. First, the photosensitive paste(conductive paste or insulating paste) is applied on such a transparentsubstrate 11 as glass substrate as illustrated in FIG. 3A and theapplied layer of the paste is dried to produce a film 12 exhibiting goodtack-free touch of finger. A photomask 13 containing a prescribed maskpattern is superposed on the film 12 and the film 12 is selectivelyexposed to light through the photomask 13 (FIG. 3B). After the removalof the photomask 13, the exposed film 12 is developed to remove theunexposed portions and assume the prescribed pattern (FIG. 3C). In thiscase, an organic solvent or an aqueous alkaline solution, for example,is used as the developing solution. When the photosensitive organiccomponent of the photosensitive paste to be used herein contains a freecarboxyl group, the development can be effected by using such an aqueousalkaline solution as sodium hydroxide, potassium hydroxide, sodiumcarbonate, potassium carbonate, sodium phosphate, sodium silicate,ammonia, or amine.

When the patterned film is formed by the printing method, such apatterned film 12 as illustrated in FIG. 3C is formed directly on thesubstrate by screen printing.

Thereafter, a heat decomposable resin composition is applied asillustrated in FIG. 3D to form a coating film 14 in such a manner as tocover the patterned film 12. Then, the superposed films are treated at aprescribed temperature, depending on the photosensitive paste usedherein, to effect removal of the binder and calcination and consequentlyform on the substrate 11 a patterned calcined film 15 (electroconductingfilm or insulating film) of the inorganic material as illustrated inFIG. 3E.

FIGS. 4A through 4G represent a process for the formation of a patternedcalcined inorganic film by the sand blasting method. First, aphotosensitive dry film 16 having the ability to resist blasting islaminated on the film 12 formed in advance by applying a pastycomposition (conductive paste or insulating paste) on the substrate 11as illustrated in FIG. 4A. Then, the photomask 13 containing theprescribed mask pattern is superposed on the dry film 16 and the dryfilm 16 is exposed to light through this photomask 13 (FIG. 4B). Afterthe removal of the photomask 13, the substrate is subjected todevelopment to remove the unexposed portions of the film 16 and obtainthe patterned film 16 (FIG. 4C).

Subsequently, blast powder 17 is blown against the film 16 asillustrated in FIG. 4D to remove the bare portions of the film 12 asillustrated in FIG. 4E. Then, the dry film 16 is peeled and removed bythe use of a remover. As the remover, an aqueous alkaline solution suchas, for example, an aqueous roughly 1% NaOH solution kept at about 40°C. or an aqueous 10 wt. % monoethanol amine solution is used. The dryfilm 16 separates from the patterned film 12 immediately when it isimmersed in this remover for a period in the approximate range of 30seconds to five minutes and then washed with water.

Thereafter, the heat decomposable resin composition is applied to formthe coating film 14 in such a manner as to cover the patterned film 12as illustrated in FIG. 4F. Then, the superposed films are treated at aprescribed temperature, depending on the pasty composition used herein,to effect removal of the binder and calcination and consequently form onthe substrate 11 the patterned calcined film 15 (electroconducting filmor insulating film) of the inorganic material as illustrated in FIG. 4G.

FIGS. 5A through 5G represent a process of forming a patterned calcinedinorganic film by the lift-off method (dry film filling method). Thisprocess is suitable particularly for the formation of ribs of the PDP.First, the photosensitive dry film 16 of a prescribed thickness islaminated on the substrate 11 as illustrated in FIG. 5A. Then, thephotomask 13 containing a prescribed mask pattern is superposed on thedry film 16. Thereafter, the film 16 is exposed to light and developedto remove the portions of the dry film 16 which has not been exposed tolight through the photomask 13 as illustrated in FIG. 5B. When atransparent substrate having electrodes of a prescribed pattern formedin advance on the surface thereof is used, the photomask is superposedon the photosensitive dry film in such a manner that the pattern windowsof the photomask are aligned with the positions of the electrodes.

Subsequently, a pasty composition (electroconductive paste or insulatingpaste) 19 is applied to the patterned dry film 16 as illustrated in FIG.5C so as to fill up grooves 18 between patterns of the dry film 16 whichhas been formed by the exposure to light and the development mentionedabove. The applied layer of the composition is defoamed, preferablyunder reduced pressure, and then dried. Since this operation inducesextinction of foam and depression of the paste part as illustrated inFIG. 5C, the cycle of application--defoaming--drying of the paste isperformed, when necessary, up to several repetitions. In this operation,the drying is desired to be carried out slowly lest the solvent in thepasty composition, on being volatilized, should leave residual bubblesbehind in the composition. The drying operation is properly performed atabout 80° C. for 30 minutes, for example, to ensure removal of bubbles.Thereafter, the paste is thermally cured at a temperature in theapproximate range of 150° C. to 160° C. for 30 to 60 minutes. The curedhot paste is cooled and then the surface thereof is polished till thedry film 16 appears (FIG. 5D).

Subsequently, the dry film 16 is peeled and removed by the use of aremover to form on the substrate 11 the patterned film 12 in theprescribed pattern as illustrated in FIG. 5E. As the remover, an aqueousalkaline solution such as, for example, an aqueous 3-5% NaOH solutionkept at 40° C. or an aqueous 10 wt. % monoethanol amine solution isused. The dry film 16 is swelled and separated from the substrateimmediately when it is immersed in the remover for a period in theapproximate range of 15 to 20 minutes and then immersed in water at atemperature in the neighborhood of 40° C. for some tens of seconds.

Thereafter, the heat decomposable resin composition is applied to formthe coating film 14 in such a manner as to cover the patterned film 12as illustrated in FIG. 5F. Then, the superposed films are treated at aprescribed temperature, depending on the photosensitive paste usedherein, to effect removal of the binder and calcination and consequentlyform on the substrate 11 the patterned calcined film 15(electroconducting film or insulating film) of the inorganic material asillustrated in FIG. 5G.

A liquid developable photosensitive resist may be used in the place ofthe photosensitive dry film used in the methods described above.

Now, the present invention will be described more specifically belowwith reference to working examples. Wherever "parts" and "%" arementioned hereinbelow, they invariably refer to those based on weightunless otherwise specified.

The glass frit used in the following Examples and Comparative Exampleswas that obtained by grinding a glass composition containing 70% of PbO,1.5% of B₂ O₃, 23% of SiO₂, 1.5% of Al₂ O₃, and 4% of BaO and having asoftening point of 522° C. and an average particle diameter of 2.0 μm.

EXAMPLES 1-4

    ______________________________________                                        Silver paste I (one layer-grade silver paste)                                 ______________________________________                                        Resin (MMA-MA-GMA)         100    parts                                       (a copolymer resin, Mw about 10,000, acid value 60                            mg KOH/g, double bond equivalent about 1,000; obtained                        by adding 0.11 mol of glycidyl methacrylate (GMA) to a                        copolymer of methyl methacrylate (MMA) and methacrylic                        acid (MA) (MMA:MA in molar ratio = 0.77:0.23)                                 Trimethylol propane triacrylate                                                                          25     parts                                       2-Methyl-1-[4-(methylthio)phenyl]-2-morpholino-                                                          2.5    parts                                       propan-1-one)                                                                 (photopolymerization initiator manufactured by Ciba                           Specialty Chemicals Inc. and sold under the trademark                         designation of "Irgacure 907")                                                Diethylene glycol n-butyl ether                                                                          75     parts                                       Silver powder              630    parts                                       Glass frit                 120    parts                                       Phosphorous acid           1      part                                        ______________________________________                                    

Preparation of test substrate

Step--1

The silver paste I of the composition shown above was applied to the topface of a glass substrate throughout the whole area by the use of a300-mesh polester screen. Then, the applied layer of the silver pastewas dried in a hot air circulating drying oven at 90° C. for 20 minutesto give a tack-free film. By using a negative film adapted to form aline/space of 70/90 μm and a metal halide lamp as a light source, thefilm was subsequently exposed to light till a calculated dose of 1,000mJ/cm² on the film. Thereafter, the photocured film was developed withan aqueous 1 wt. % Na₂ CO₃ solution of 30° C.

Step--2

On the patterned surface of the glass substrate which completed thestep--1 mentioned above, a varying heat decomposable resin compositionshown below was applied by printing throughout the entire area by theuse of a 300-mesh polyester screen. Thereafter, in Example 1, by using aUV conveyor provided with a high pressure mercury vapor lamp as a lightsource, the applied layer of the composition was exposed to UV light andcured till a calculated dose of 1,000 mJ/cm² on the composition. InExamples 2-4, after the printing of the heat decomposable resincomposition mentioned above, the applied layer thereof was dried in ahot air circulating drying oven at 90° C. for 20 minutes. The substratemanufactured under the foregoing conditions was calcined in acalcination profile comprising heating in the air till 450° C. at atemperature increasing rate of 10° C./minute, standing at rest at 450°C. for 20 minutes (for removal of the binder), heating again to 550° C.at a temperature increasing rate of 5° C./minute, heat treating in theair at 550° C. for 30 minutes, and allowing the substrate to fall toroom temperature, to obtain the test substrate.

The resultant substrate was tested for various properties. The resultsare shown in Table 1. Even when the patterned layer of silver pastemelted or suffered impairment of its adhesion to the substrate after theheat decomposable resin composition was applied to the substrate ordried, the exposure of the substrate performed up to the step--1 to UVlight by the use of a UV conveyor provided with a high pressure mercuryvapor lamp as a light source till a calculated dose of 2,000 mJ/cm²enabled the silver paste to retain a stable state after the heatdecomposable resin composition was applied to the substrate or dried.

The heat decomposable resin compositions used herein were as shownbelow.

    ______________________________________                                        Heat decomposable resin compotition A (burning-off point:                     about 540° C.)                                                         Trimethylol propane trimethacrylate                                                                       100 parts                                         Photopolymerization initiator (manufactured                                                                4 parts                                          by Merck Co. and sold under the trade-                                        mark designation of "Darocure 1173")                                          Heat decomposable resin composition B (burning-off point:                     about 520° C.)                                                         Resin (MMA-MA-GMA)           55 parts                                         Diethylene glycol n-butyl ether                                                                            45 parts                                         Heat decomposable resin composition C (burning-off point:                     about 420° C.)                                                         Acrylic polycarboxylic acid  50 parts                                         High boiling petroleum solvent (manufactured                                                               50 parts                                         by Exxon Chemical K.K. and sold                                               under the trademark designation of                                            "Solvesso #200")                                                              Heat decomposable resin composition D (burning-off point:                     about 530° C.)                                                         Resin (MMA-MA-GMA)           44 parts                                         Dipentaerythritol hexaacrylate                                                                             16 parts                                         Trimethylol propane triacrylate                                                                            2 parts                                          Irgacure 907                 2 parts                                          Diethylene glycol n-butyl ether                                                                            36 parts                                         ______________________________________                                    

Comparative Example 1

A test substrate was manufactured by following the procedure of Example1 while omitting the application of the heat decomposable resincomposition by printing to the patterned film surface of the glasssubstrate performed up to the step--1. The resultant substrate wastested for various properties. The results are shown additionally inTable 1.

                  TABLE 1                                                         ______________________________________                                                   Heat decomposable     Shrinkage of                                 Run No.    resin composition                                                                            Curl   line width                                   ______________________________________                                        Example  1     A              ⊚                                                                   ⊚                                    2     B              ⊚                                                                   ∘                                       3     C              ∘                                                                      ∘                                       4     D              ⊚                                                                   ⊚                           Comparative                                                                              --             x      x                                            Example 1                                                                     ______________________________________                                         Remark                                                                        ⊚: Perfect absence of curl or shrinkage of line width          ∘: Slightly discernible curl or shrinkage of line width           x: Clearly discernible curl, shrinkage of line width, or breakage of line

The surface profile of the patterned film manufactured in Example 4 wasmeasured by the use of a surface roughness meter. The surface profile isshown in FIGS. 6A through 6C.

FIG. 6A depicts the state of the film (about 6-8 μm in thickness) afterdevelopment, FIG. 6B the state of the film (about 2-2.5 μm in thickness)obtained after being calcined without being coated with the heatdecomposable resin composition D, and FIG. 6C the state of the film(about 2-2.5 μm in thickness) obtained after being coated with the heatdecomposable resin composition D and then calcined. It is clearly notedfrom FIG. 6B that the film, when obtained after being calcined withoutbeing coated with the heat decomposable resin composition, developedwarpage and sustained shrinkage of line width to a considerable extent.Incidentally, the rugged line of the surface of the calcined filmappearing in FIG. 6C reflects the fact that the calcined film had amicroporous structure.

Examples 5-7

    ______________________________________                                        Silver paste II (two-layer grade primer silver paste)                         ______________________________________                                        Resin (MMA-MA-GMA)        100 parts                                           Trimethylol propane triacrylate                                                                          50 parts                                           Irgacure 907               15 parts                                           Diethylene glycol n-butyl ether                                                                          75 parts                                           Silver powder             150 parts                                           Glass frit                 25 parts                                           Black pigment             100 parts                                           Phosphorous acid           1 part                                             ______________________________________                                    

Manufacture of test substrate

Step--1

The silver paste II of the composition shown above was applied to thetop face of a glass substrate throughout the whole area by the use of a300-mesh polyester screen similarly in Examples 1-4. Then, the appliedlayer of the silver paste was dried in a hot air circulating drying ovenat 90° C. for 20 minutes to give a tack-free film. Subsequently, thesilver paste I for the upper layer used in Examples 1-4 was applied byprinting and dried under the same conditions as mentioned above to forma second layer. By using a negative film adapted to form a line/space of70/90 μm and a metal halide lamp as a light source, the superposed filmswere subsequently exposed to light till a calculated dose of 1,000mJ/cm² on the films. Thereafter, the photocured films were developedwith an aqueous 1 wt. % Na₂ CO₃ solution of 30° C.

Step--2

On the patterned film surface of the glass substrate which completed thestep--1 mentioned above, the varying heat decomposable resin compositionshown above was applied by printing throughout the entire area by theuse of a 300-mesh polyester screen. Thereafter, the resultant substratewas dried and calcined under the same conditions as in Examples 1-4 toproduce the test substrate.

The resultant substrate was tested for various properties. The resultsare shown in Table 2. Even when the patterned layer of silver pastemelted or suffered impairment of its adhesion to the substrate after theheat decomposable resin composition was applied to the substrate ordried, the exposure of the substrate performed up to the step--1 to UVlight by the use of a UV conveyor provided with a high pressure mercuryvapor lamp as a light source till a calculated dose of 2,000 mJ/cm²enabled the silver paste to retain a stable state after the heatdecomposable resin composition was applied to the substrate or dried.

Comparative Example 2

A test substrate was manufactured by following the procedure of Example5 while omitting the application of the heat decomposable resincomposition by printing to the patterned film surface of the glasssubstrate performed up to the step--1. The resultant substrate wastested for various properties. The results are shown additionally inTable 2.

                  TABLE 2                                                         ______________________________________                                                   Heat decomposable     Shrinkage of                                 Run No.    resin composition                                                                            Curl   line width                                   ______________________________________                                        Example  5     B              ⊚                                                                   ∘                                       6     C              ∘                                                                      ∘                                       7     D              ⊚                                                                   ⊚                           Comparative                                                                              --             x      x                                            Example 2                                                                     ______________________________________                                         Remark: The symbols have the same meanings as defined above.             

As evidenced above, since the method of the present invention, for thepurpose of producing an electroconductive film or an insulating film(nonconductive film) by performing a calcining operation on a patternedfilm on a substrate, comprises covering the patterned film with acoating film of a heat decomposable resin composition prior to thecalcining step mentioned above and thereafter performing the calciningstep, it is capable of producing a patterned calcined inorganic filmwithout inducing warpage, shrinkage of line width, or breakage ofpatterned lines.

The method of the present invention is useful for all the technicalfields embracing the step of calcining a patterned film such as theformation of a circuit on a ceramic substrate, the manufacture of aphotoelectric tube, the manufacture of an electroconductive film or aninsulating film on the front substrate or the back substrate of a plasmadisplay panel. In the production of the PDP particularly, this methodcan form finely patterned electroconducting films such as bus electrodesand address electrodes and insulating films of the ribs with highaccuracy without inducing warpage or shrinkage of line width. When thismethod is used for the formation of a fluorescent film, it can producethe PDP of high quality because it precludes the occurrence of a crackin the fluorescent film.

While certain specific working examples have been disclosed herein, theinvention may be embodied in other specific forms without departing fromthe spirit or essential characteristics thereof. The described examplesare therefore to be considered in all respects as illustrative and notrestrictive, the scope of the invention being indicated by the appendedclaims rather than by the foregoing description and all changes whichcome within the meaning and range of equivalency of the claims are,therefore, intended to be embraced therein.

What is claimed is:
 1. In a method for the production of a plasmadisplay panel including the steps of:patterning a film of a compositioncontaining a heat decomposable binder and particles of an inorganicmaterial formed on a substrate and calcining said film thereby burningoff said heat decomposable binder and consequently forming on saidsubstrate a patterned electroconducting or insulating film made of saidinorganic material, the improvement comprising prior to said calciningstep, covering said film with a coating film of a heat decomposableresin composition capable of hardening or drying at a temperature lowerthan the temperature at which said heat decomposable binder is thermallydecomposed and further capable of being burned off at a temperature notmore than the highest temperature of the calcining profile andthereafter performing said calcining step.
 2. The method according toclaim 1, wherein said heat decomposable resin composition contains afilm-forming component possessing a burning-off temperature in the rangeof 300° C. to 600° C.
 3. The method according to claim 1, wherein saidheat decomposable resin composition contains a film-forming componentidentical with said heat decomposable binder.
 4. The method according toclaim 1, wherein said heat decomposable resin composition contains afilm-forming component having a burning-off temperature substantiallyequal to a burning-off temperature of said heat decomposable binder. 5.The method according to claim 1, wherein said heat decomposable resincomposition is a photocurable resin composition.
 6. The method accordingto claim 5, wherein said photocurable resin composition contains acompound having at least one ethylenically unsaturated bond in itsmolecule and a photopolymerization initiator.
 7. The method according toclaim 1, wherein said heat decomposable resin composition is a dryingresin composition.
 8. The method according to claim 1, wherein said heatdecomposable resin composition is a thermosetting resin composition. 9.In a method for the production of a plasma display panel including:afilm-forming step of forming on a substrate a coating film of a pastycomposition containing a heat decomposable binder and particles of aninorganic material and possessing an ability to render itself, onexposure to light, insoluble in a developing solution, an exposing stepof selectively exposing said film to light thereby photocuring anexposed portion of said film, a developing step of removing an unexposedportion of said film with a developing solution, and a calcining step ofcalcining said photocured film together with said substrate therebyburning off said heat decomposable binder in said film and consequentlyforming on said substrate a patterned electroconducting or insulatingfilm of said inorganic material, the improvement comprising prior tosaid calcining step, covering said photocured film with a coating filmof a liquid heat decomposable resin composition capable of hardening ordrying at a temperature lower than the temperature at which said heatdecomposable binder is thermally decomposed and further capable of beingburned off at a temperature not more than the highest temperature of thecalcining profile and thereafter performing said calcining step.
 10. Themethod according to claim 9, wherein said heat decomposable resincomposition contains a film-forming component possessing a burning-offtemperature in the range of 300° C. to 600° C.
 11. The method accordingto claim 9, wherein said heat decomposable resin composition contains afilm-forming component identical with said heat decomposable binder. 12.The method according to claim 9, wherein said heat decomposable resincomposition is a photocurable resin composition.
 13. The methodaccording to claim 9, wherein said heat decomposable resin compositionis a drying resin composition.
 14. In a method for the production of aplasma display panel including:a film-forming step of forming on asubstrate a coating film of a pasty composition containing a heatdecomposable binder and particles of an inorganic material andpossessing an ability to render itself, on drying or hardening,susceptible of an abrading work with blast powder, a resist-forming stepof laminating a blast-resistant photosensitive dry film on said coatingfilm, selectively exposing said photosensitive dry film to light, andthen developing said dry film thereby forming a blast-resistant filmpossessing a prescribed masking pattern, a blasting step of blowingblast powder to said films thereby cutting a portion of said coatingfilm exposed through said blast-resistant film to give a patterned film,a peeling step of removing said bast-resistant film with a remover, anda calcining step of calcining said blast-worked patterned film togetherwith said substrate thereby burning off said heat decomposable binder insaid patterned film and consequently forming on said substrate apatterned electroconducting or insulating film of said inorganicmaterial, the improvement comprising prior to said calcining step,covering said patterned film with a coating film of a liquid heatdecomposable resin composition capable of hardening or drying at atemperature lower than the temperature at which said heat decomposablebinder is thermally decomposed and further capable of being burned offat a temperature not more than the highest temperature of the calciningprofile and thereafter performing said calcining step.
 15. The methodaccording to claim 14, wherein said heat decomposable resin compositioncontains a film-forming component possessing a burning-off temperaturein the range of 300° C. to 600° C.
 16. The method according to claim 14,wherein said heat decomposable resin composition contains a film-formingcomponent identical with said heat decomposable binder.
 17. The methodaccording to claim 14, wherein said heat decomposable resin compositionis a photocurable resin composition.
 18. The method according to claim14, wherein said heat decomposable resin composition is a drying resincomposition.
 19. In a method for the production of a plasma displaypanel including:a filling step of applying a pasty compositioncontaining a heat decomposable binder and particles of an inorganicmaterial in a prescribed thickness to a dry film having grooves on asubstrate so as to fill up said grooves and drying and hardening saidcomposition, a polishing step of polishing a film of said hardenedcomposition till said dry film appears to the surface, a peeling step ofimmersing said dry film and said substrate in a remover to swell andpeel off said dry film thereby leaving a patterned film of said hardenedcomposition, and a calcining step of calcining said patterned film ofthe hardened composition together with said substrate thereby burningoff said heat decomposable binder in said hardened composition andconsequently forming on said substrate a patterned electroconducting orinsulating film of said inorganic material, the improvement comprisingprior to said calcining step, covering said patterned film of thehardened composition with a coating film of a liquid heat decomposableresin composition capable of hardening or drying at a temperature lowerthan the temperature at which said heat decomposable binder is thermallydecomposed and further capable of being burned off at a temperature notmore than the highest temperature of the calcining profile andthereafter performing said calcining step.
 20. The method according toclaim 19, wherein said heat decomposable resin composition contains afilm-forming component possessing a burning-off temperature in the rangeof 300° C. to 600° C.
 21. The method according to claim 19, wherein saidheat decomposable resin composition contains a film-forming componentidentical with said heat decomposable binder.
 22. The method accordingto claim 19, wherein said heat decomposable resin composition is aphotocurable resin composition.
 23. The method according to claim 19,wherein said heat decomposable resin composition is a drying resincomposition.
 24. In a method for the production of a plasma displaypanel including:a printing step of forming on a substrate by screenprinting a film of a prescribed pattern of a pasty compositioncontaining a heat decomposable binder and particles of an inorganicmaterial and possessing an ability to render itself, on drying orhardening, capable of retaining the shape thereof and a calcining stepof calcining said film together with said substrate thereby burning offsaid heat decomposable binder in said film and forming on said substratea patterned electroconducting or insulating film of said inorganicmaterial, the improvement comprising prior to said calcining step,covering said film of the prescribed pattern with a coating film of aliquid heat decomposable resin composition capable of hardening ordrying at a temperature lower than the temperature at which said heatdecomposable binder is thermally decomposed and further capable of beingburned off at a temperature not more than the highest temperature of thecalcining profile and thereafter performing said calcining step.
 25. Themethod according to claim 24, wherein said heat decomposable resincomposition contains a film-forming component possessing a burning-offtemperature in the range of 300° C. to 600° C.
 26. The method accordingto claim 24, wherein said heat decomposable resin composition contains afilm-forming component identical with said heat decomposable binder. 27.The method according to claim 24, wherein said heat decomposable resincomposition is a photocurable resin composition.
 28. The methodaccording to claim 24, wherein said heat decomposable resin compositionis a drying resin composition.